Flexibility
KIN 325
1. Definition
The range of motion that can be elicited
at a particular joint or group of joints
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Range of motion is highly specific; it
differs between joints
Also varies between people due to:
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genetics and gender
physical activity level
joint structure
• age
• tissue injury
• adipose tissue
• body temperature
2. The benefits of a flexibility training program
• Maintain good joint mobility, allowing for
proper body mechanics
• Reduce mechanical stress within the joints
• Muscular relaxation
• Relief of muscular cramps
• Increase resistance to muscle injury
• Improve and maintain good postural alignment
• Prevent low-back and other spinal column problems
3. Connective Tissue: a limiting factor for
flexibility
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Joint capsule and associated ligaments contribute
approximately 47% to restriction of ROM; muscles
contribute 41%, the tendons 10%, and skin 2%
Stretching exercises help to cause minor distensions in
connective tissue and summation of these small changes can
improves ROM
Increase in stretch tolerance
4. Sensory Receptors Related to Stretching
a. Muscle spindles
Primary stretch receptors in muscle, encased in a spindle-shaped
capsule which is attached at both ends to the muscle fibers
b. Golgi tendon organs
Located at the muscle-tendon junction, not within the tendon.
Main function is to monitor muscle tension
5. Stretching methods
a. Ballistic stretching
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Associated with bobbing or bouncing. Fast, dynamic stretches.
Advantages:
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Develops dynamic flexibility
Permits specificity of training
Disadvantages
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Quick stretch allows little time for adaptation. Permanent
lengthening is most effectively achieved by lower force, longer
duration stretches
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Fast stretches create high tensile forces. Can result in injury
or muscle soreness
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Might elicit the stretch reflex. Causes muscle contraction,
therefore increases tension.
b. Static stretching
• a static position held for a period of time
Advantages:
• muscle soreness minimized
• injury risk minimized
• more effective than ballistic stretching for increasing
ROM
Disadvantages:
• Not specific to many movements where dynamic
flexibility is required
c. Proprioceptive Neuromuscular Facilitation (PNF)
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Incorporates various combinations of relaxation and
contraction periods for the muscles being stretched
The theory is that a simple reflex, initiated by the Golgi
tendon organs during the contraction phase, will cause
the muscle to relax more and offer less resistance to
the stretch
Contract-relax method - autogenic inhibition
A variation of this method is the contract relax with
agonist contraction (CRAC) technique – also
incorporates reciprocal inhibition
Advantages:
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Most research shows this method produces the largest gains
in flexibility
Also develops strength in the muscle as large forces are
developed when the muscle is isometrically contracted in
stretched position
Disadvantages
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Elicits the most discomfort
DOMS can result
Greater risk of injury than with static stretching
Usually requires a partner
Not recommended for patients with CVD, as blood pressure
might rise too high
6. Exercise Prescription
Mode: static or PNF
Frequency: at least 3 days per week
Intensity: to point of discomfort, not pain
Duration: 10 to 30 seconds each stretch
Repetition: 3 to 5 for each stretch